There a lot of information in EVGA forums and http://hardforum.com/showthread.php?t=1556078 Please find out according to you CPU.
I run my single X5677 as well aircooled 180@4500 Cpu Vcore 1,4875 VTT 1,5 IOH 1,425. Almost month now.
Not polite for CPU considering long benchmark sessions but briefly gives a hint what to expect if going with watercooling